The natural sense of hearing in human beings involves the use of hair cells in the cochlea that convert or transduce acoustic signals into auditory nerve impulses. Hearing loss, which may be due to many different causes, is generally of two types: conductive and sensorineural. Conductive hearing loss occurs when the normal mechanical pathways for sound to reach the hair cells in the cochlea are impeded. These sound pathways may be impeded, for example, by damage to the auditory ossicles. Conductive hearing loss may often be overcome through the use of conventional hearing aids that amplify sound so that acoustic signals can reach the hair cells within the cochlea. Some types of conductive hearing loss may also be treated by surgical procedures.
Sensorineural hearing loss, on the other hand, is caused by the absence or destruction of the hair cells in the cochlea which are needed to transduce acoustic signals into auditory nerve impulses. People who suffer from sensorineural hearing loss may be unable to derive significant benefit from conventional hearing aid systems, no matter how loud the acoustic stimulus. This is because the mechanism for transducing sound energy into auditory nerve impulses has been damaged. Thus, in the absence of properly functioning hair cells, auditory nerve impulses cannot be generated directly from sounds.
To overcome sensorineural hearing loss, numerous cochlear implant systems—or cochlear prostheses—have been developed. Cochlear implant systems bypass the hair cells in the cochlea by presenting electrical stimulation directly to the auditory nerve fibers by way of one or more channels formed by an array of electrodes implanted in the cochlea. Direct stimulation of the auditory nerve fibers leads to the perception of sound in the brain and at least partial restoration of hearing function.
When an implantable cochlear device of a cochlear implant system is initially implanted in a patient, and during follow-up tests and checkups thereafter, it is usually necessary to fit the cochlear implant system to the patient. Fitting of a cochlear implant system to a patient is not an exact science but an ongoing trial-and-error-based iterative exercise that is largely dependent on the experience of and feedback provided by the patient. For example, in a fitting session, an audiologist or the like typically utilizes a fitting system to present various stimuli to the patient and relies on subjective feedback from the patient as to how such stimuli are perceived. Based on this process, the audiologist utilizes the fitting system to configure the cochlear implant system for operation.
It is not uncommon, however, for a patient to be unsatisfied with modifications made to a configuration of a cochlear implant system during a fitting session. For example, after trying out a current configuration for a period of time, a patient may feel that the current configuration is inferior to a previous configuration of the cochlear implant system. However, a configuration of a cochlear implant system is typically a complicated aggregation of sound processing programs and other settings that when considered in combination may produce any of a large number of permutations. Consequently, an audiologist using a conventional fitting system faces a difficult task when asked by a patient to restore a cochlear implant system to a previous configuration. Even if the audiologist has detailed notes of the previous configuration, the use of such notes to restore the cochlear implant system to the previous configuration is prone to error, time consuming, inconvenient, and/or potentially frustrating to the audiologist and/or the patient.